1. Field of the Invention
This invention concerns a heat processing device using butane or like other liquefied gas as a fuel and, more specifically, it relates to a heat processing device using a liquefied gas capable of controlling the flow rate of air to be mixed with the fuel gas.
2. Description of the Prior Art
There have generally been known various types of heat processing devices, for example, a traditional blow or torch lamp in which a gas mixture composed of liquefied gas and air is jetted out from a fire nozzle member, followed by ignition, as well as a soldering iron, for example, disclosed by Sim in U.S. Pat. No. 4,119,088. There has further been known an improved catalytic combustion type soldering iron in which the gas mixture is put to flameless complete combustion in contact with the combustion catalyst and an iron tip is heated by the heat of the catalytic combustion as disclosed in Japanese Patent Publications Nos. 6033/1980 and 29789/1980.
However, the conventional heat processing devices of these types were restricted respectively in their application uses and those devices capable of serving both for a blow or torch lamp and a soldering iron were not known.
In view of the above, the present inventor has already proposed a heat processing device capable of serving both for the soldering iron and the blow or torch lamp of the catalytic combustion type as disclosed in our Japanese Patent Application No. 159850/1984, as well as in our U.S. Pat. No. 4,552,124.
In our prior application and prior patent, the heat processing device can be used as a soldering iron by igniting a gas mixture composed of liquefied gas and air jetted out from a fire nozzle member, heating the combustion catalyst by the heat of the ignition flame to a temperature capable of complete combustion by the catalytic oxidation and then extinguishing the pilot flame at the fire nozzle member by closing the air port or space formed between the iron tip member and the fire nozzle member by a shutter, or by displacing the iron tip member and the fire nozzle member axially relative to each other thereby closing the space between them. This heat processing device can also be used as a blow lamp by detaching the iron tip member. It can further be used as a torch by closing the external air intake port under the state where the device is used as the blow lamp while using the flame from the fire nozzle member as a flame like that in a gas lighter.
By the way, in the case of using the heat processing device of this type as a blow lamp, it is desirable to adjust the temperature at the top end of the flame depending on the kinds of materials to be fabricated, the way of fabrication, etc. However, temperature change can not be attained with ease unless the gas flow rate is controlled to change the size of the flame and, further, it is difficult to obtain a desired temperature even if the gas flow rate is thus controlled.
Sim discloses in his U.S. Patent as cited above, a mechanism for controlling the temperature of the gas flame by regulating the open area of main air intake holes, etc., thereby varying the air flow entering the air intakes. However, mere regulation for the entering air flow is not practically suitable to the application use as the hot blow, where strict and accurate temperature control is required, for example, each by 100.degree. C. step depending on the works. Blow lamp users would encounter a difficulty upon using the Nigel's control mechanism, because they have to judge the temperature change, for example, by the color of the gas flame. Such a measure is too rough to determine the exact temperature of the blow flame, although it may be effective for the temperature control of the iron bit as in Sim.
In addition, his soldering iron does not use the principle of the catalytic combustion that was developed by us for the complete flameless and safety combustion.
In the case of using the neat processing device as a soldering iron by disposing an iron tip to the top end of the fire nozzle member, if the scale of the device is enlarged in order to obtain an increased thermal power, it takes a considerable time to extinguish the pilot flame at the fire nozzle member and there is even a possibility that the flame can not be put off even if the space between the iron tip and the fire nozzle member is shut. It is essential in the catalytic combustion type soldering iron to extinguish the pilot flame without fail at least in the stage of actual soldering work as stated in our U.S. Patent.